This invention relates to cultivators of the type which include a plurality of tools that engage and till the soil.
The prior art includes a wide variety of cultivating implements designed for both pre-planting use and for cultivating at various stages of crop growth. Many prior art implements, commonly called "rotary hoes", were designed to cover large areas of a field with closely spaced rotary tools. The prior art also discloses a variety of cultivating implements having multiple rotary tools, each of which may be angled with respect to the line of draft of the implement.
One such example of a prior art implement is shown in U.S. Pat. No. 1,249,008 to W. P. Bonds, Jr. The implement shown in the Bonds patent has a plurality of laterally spaced rotary ground engaging tools suspended from a transverse bar with means for simultaneously raising all of the tools away from the ground and a spring assembly for individually urging each of the tools down into the ground. Bonds also discloses structure which enables the tools to be selectively angled with respect to the line of draft of the implement by means of a collar and shaft arrangement for each rotary tool and a set screw which extends through the collar and can be brought into engagement with the shaft.
The disadvantages of most of the prior art adjustable implements include the necessity for using a wrench or other hand tool when adjusting the angle of draft of each ground engaging tool, that the rotary tools are raised or lowered from the ground in unison, that a visual aid such as a protractor is required for accurately setting the angle of draft of the rotary tool, that some type of external measuring device is required for accurate placement of various tools along the length of a tool bar when assembling the implement, and that certain ones of the tools already mounted on a tool bar must be removed from the tool bar when it is desired that certain portions of the width of the implement be free from ground engaging tools as when cultivating about growing crops, etc.